Oligomericzation process



United States Patent 3,390,195 OLIGOMERHZATION PRGCESS Sterling F. Chappell III, and Jerome R. Olechowslri, Lake Charles, and Arthur A. Arseueaux, New Orleans, La., assignors to Colombian Carbon Company, New York, N.Y., a corporation of Delaware No Drawing. Filed Oct. 5, 1966, Ser. No. 584,379 Claims. (Cl. 260-666) This invention relates to the production of oligomers of conjugated diolefins. More particularly, in one respect, the invention provides a highly effective process for homooligomerizing 1,3 butadiene or like conjugated diolefins to dimer and/ or trimer oligomers thereof. In another respect, the invention is concerned with a process for interacting 1,3-butadiene with a ec-monomer to produce useful cooligomer products.

It is known to oligomerize butadiene or like conjugated diolefins by contacting the diolefin or a mixture of diolefin and ethylene in the liquid phase with a preformed molecular organic Lewis base complex of nickel (0), such as one having the structural formula: (L) Ni(CO) wherein L is a molecular Lewis base, preferably an ester of a trivalent Group V-A element having an atomic weight of from about to about 209, and n is an integer from 0 to 4 inclusive. Catalyst compositions of this type have heretofore been prepared by contacting nickel tetra carbonyl with an organic molecular Lewis base, such as triphenyl arsine, optionally in the presence of an activator compound, such as triethylaluminum. While such preformed complexes are effective in the homo-oligomeri zation of butadicne or the co-oligomerization of butadiene and ethylene, but they have not been widely used commercially because of their limited availability, a fact attribu'table largely to the difficulty and expense involved in their conventional synthesis from extremely toxic nickel tetra carbonyl.

An alternate known procedure, which avoids the necessity of handling nickel tetra carbonyl and which generally can be conducted under somewhat milder reaction conditions, involves oligomerizing a conjugated diene, such as butadiene, in the presence of a positive valence nickel compound and a metal alkyl, such as triethylaluminum. The catalyst composition which is prepared in situ in such reaction system is believed to be a complex of the Lewis base diene and nickel (0). A major disadvantage of this method is that the reaction rate is relatively slow and as much as 24 hours or more may be required to achieve reasonable monomer conversion levels.

Accordingly, it is an object of the present invention to provide an improved process for oligomerizing or cooligomerizing butadienc or like conjugated dienes to cyclic and/ or acyclic oligomers.

It is another object of the invention to provide an improved process oligomerizing two (2) moles of butadiene and one (l) mole of a co-monomer, e.g. ethylene.

It is a further object of the invention to provide an improved process for producing cyclic triolefins containing twelve (l2) carbon atoms in the cyclic ring in high yield.

It is another object of the invention to provide an improved process for oligomerizing or co-oligomerizing butadiene or like conjugated dienes to cyclic and/ or acyclic oligomers, whereby the reaction is effected at a relatively rapid we and the desired product(s) is recovered in high yields.

Various other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description thereof.

The present invention is predicated on our discovery that conjugated diolefinic hydrocarbons may be effectively oligomerized by contacting the diolefin with a catalyst composition produced by admixing the diene, under sub stantially anhydrous conditions, with a nickel (positive valence) compound, a metal alkyl, such as triethyl aluminum, and carbon monoxide. More particularly, we have now surprisingly found that such catalyst composition permits the homo-oligomerization of conjugated diolefins or co-oligomerization of conjugated diolefins with a comonomer to proceed at a decidedly more rapid rate than the prior art in situ catalysts as described above. Furthermore, we have found that the homo-oligomerization of l,3-butadiene according to the process of our present invention results in exceptionally high selectivities of cyclododecatriene (C products, e.g. 1,5,9-cyclododecatriene, and the co-oligomerization of butadiene and ethylene results in exceptionally high selectivities of C oligomers, e.g. 1,5-cyclodecadiene and l,4,9-decatriene.

Butadiene is the preferred conjugated aliphatic diolefin employed as the starting material of this invention. However, other l,3-dienes are also useful, particularly 2- methyl-l,3-butadiene (isoprene); 2-ohloro-1,3-butadiene (chloroprene); 2,3-dichloro-1,3-butadiene; 1,3-pentadiene (piperylene); 2,3-dimethyl-1,3-butadiene; and phenyldiolefins. Partially substituted halogen derivatives may be used, including mixed halogen derivatives, such as ch-loro-fluoro- 1,3-butadienes. Other open chain conjugated dienes such as 2,4-hexadicne are also somewhat useful. If desired, peroxides may be removed from. the diene feed by treatment with ferrous salts, thiosulfates, or sulfites, according to available methods.

As previously noted, the conjugated diolefins may be rapidly oligomerized in accordance with this invention to produce predominantly cyclic oli-gorners, particularly those having twelve (12) carbon atoms in the carbocyclic ring, such as 1,5,9-cyclododecatriene. The present process is also useful in the co-oligomerization of conjugated dienes with a co-monomer selected from the group consisting of hydrocarbons having the formula:

wherein A is selected from the group consisting of phenyl and hydrogen radicals, acetylenic hydrocarbons, vinyl halides and a,B-unsaturated carbonyls and nitriles. Exemplary of specific co-monomers are ethylene, styrene, divinylbenzene, vinyl chloride, acetylene, propyne, acrolein, crotonaldehyde, methyl acrylate, methyl methacrylate and acrylonitrile. The preferred co-monomers are ethylene and styrene. Thus, the co-oligomerization of two (2) moles of butadiene and one (1) mole of ethylene may be effected in accordance with the present process to produce cyclic diolefins containing ten (10) ring carbon atoms, such as l,5-cyclodecadiene, in high yields, as well as normal decatrienes. Likewise, 1,3-butadiene (2 moles) and styrene (1 mole). may be co-oligomerized to l-phenyl derivatives of cyclic and normal unsaturated hydrocarbons, such as l-phenyl-1,4,9-decatriene and 1- phenyl-3,7-cyclodecadiene.

Broadly, the catalyst compositions which we have found to be useful in the practice of the present invention are prepared by admixing under substantially anhydrous conditions a nickel (positive valence) compound, a reducing agent capable of reducing the valence of nickel to below 2 (e.g. 0), a molecular organic Lewis base and carbon monoxide. In general, any nickel compound having a formal valence of +2 or +3 is useful in preparing the catalyst composition. Examples of such suitable nickel sources include inorganic nickel compounds, such as nickel bromide, nickel carbonate, nickel chloride, nickel chlorate, nickel cyanide, nickel ferrocyanide, nickel fluoride, nickel hydroxide, nickel iodide, nickel nitrate, nickel oxide, nickel orthophosphate and nickel sulfate; organic nickel compounds, such as nickel acetate, nickel benzene sulfonate, nickel benzoate, nickel citrate, nickel Z-ethylhexonate, nickel naphthenate, nickel oxalate, nickel stearate, nickel acetylacetonate, nickel benzoylacetonate and nickel dimethylglyoxime; complexes of inorganic nickel salts, such as tris(N-methylpyrrolidone) nickel (II) bromide. From a practical viewpoint, it is often desirable to prepare the catalyst utilized in the practice of this invention in a hydrocarbon solvent. Accordingly, nickel compounds which have a significant solubility in such hydrocarbons represent a preferred group. Illustrative of this preferred group are the nickel salts of carboxylic acids containing at least six (6) carbon atoms, halogen acids and nickel compounds of organic chelating groups such as acetylacetone, benzoylacetone, climethylglyoxime, glycine, 8-hydroxyquinoline, nitrosophenylhydroxylarnine and salicylaldenyde.

Any reducing agent which is capable under substantially anhydrous conditions of lowering the valence of nickel in a normal oxidation state of two or three to a value of less than two, and preferably to zero, is suitable for use in the present invention. Illustrative of such reducing agents are hydrogen, the hydrazines, and metals of Groups I-A, lI-A, IIB, llI-A and lV-A, as well as hydride and organometallic compounds of these metals and of boron. Specific examples of suitable reducing agents include hydrazine, methyl hydrazine, unsymmetrical dimethyl hydrazine, lithium, sodium, potassium, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, gallium, indium, germanium, tin, lead, n-butyl lithium, phenyl sodium, allyl sodium, sodium hydride, diethyl magnesium, phenyl magnesium bromide, calcium hydride, diethyl zinc, mercuric hydride, aluminum hydride, trimethylaluminum, tricyclohexylaluminum, diethylaluminum chloride, ethylaluminum dichloride, ethoxydiethylaluminum, diisobutylaluminum hydride, tctraethyl lead, diborane, dimethyl borane, tetraborane, lithium aluminum hydride, and sodium aluminum tetraethyl. The use of the hydride and organometallic compounds of the aforementioned nontransition metals, which represent a preferred group of reducing agents, results in a particularly active and selective catalyst composition for use in the practice of the invention and facilitates the isolation of the desired homooligomers or co-oligomers from the reaction mixture.

An especially preferred group of reducing agents can be represented by the formula: R AlY, wherein R is a hydride or hydrocarbyl radical, X is a halide or hydrocarboxy radical, a is from 1 to 3, b is from O to 2 and the sum of a plus b is 3. Illustrative of such compounds are trimethylaluminum, triethylaluminum, trii-butylaluminum, trioctylaluminum, tridodecylaluminum, tricyclohexylaluminum, triphenylaluminum, tritolylaluminum, ethoxydiethylaluminum, diethoxyethylaluminum, butylaluminum dihydride, diethylphenylaluminum, aluminum trihydride, diethylaluminum chloride, monoethylaluminum dichloride and ethylaluininum sesquihalide, i.e. a mixture of diethylaluminum chloride and ethylaluminum dichloride or a mixture of triethylaluminum and aluminum trichloride. Particularly preferred aluminum compounds for the purposes of this invention are the trialkylaluminum compounds.

Any molecular organic Lewis base can be admixed with carbon monoxide, the nickel compound and the reducing agent in preparing the catalyst compositions utilized in the practice of the present invention. As used herein and in the appended claims, the term molecular organic Lewis base is intended to designate any organic molecule having at least one pair of electrons available for sharing with nickel. Such compounds are well known in the art and include ethylenically-unsaturated hydrocarbons, ethers, hydrocarbyl esters of sulfur acids, heterocyclic sulfur compounds, and organic derivatives of trivalent Group VA elements.

Exemplary of ethylenically-unsaturated hydrocarbons suitable as Lewis bases are the conjugated diolefins utilized as the starting materials of the present process, such as 1,3-butadiene, isoprcne, piperylene, and the like. Cyclic aliphatic compounds containing at least two double bonds and one or more carbocyclic rings, the unsaturation being in a single ring or in adjoining rings, are also useful. Thus, bridged-ring multi-enes, such as bicyclo (2.2.1) hepta-2,5-diene (norbornadiene), 2-methylnorbornadiene, 2-propylnorbornadiene, 2-i-propylnorbornadiene, 2-n-butylnorbornadiene, Z-i-butylnorbornadiene, 2-t-butylnorbornadiene, Z-n-amylnorbornadiene, 2-(3- methyl) butylnorbornadiene, Z-neopentylnorbornadicne, Z-n-hexylnorbornadiene, 2-n-octylnorbornadiene, 2-nhexylnorbornadiene, 2-n-octylnorbornadiene, 2-n-nonylnorbornadiene, 2-n-dodecylnorbornadiene, Z-n-heptadecylnorbornadiene, bicyclopentadiene, bicyclo (2.2.2) octa-2,5-diene and bicyclo (3.2.1) octa-2,5-diene may be employed, for instance. Furthermore, single ring carbocyclic multi-enes may be used including 1,5-cyclooctadiene, 1,3-cyclooctadiene, dimethyl-1,5-cyclooctadiene, l,5,9-cyclododecatriene, 1,5-cyclodecadiene, 1,6-cyclodecadiene, 1,5-cyclododecadiene, 1,3-cyclododecadiene and 1,3-cyclohexadiene may be used. In addition, functionally-substituted olefins are also somewhat useful as Lewis bases. For instance, compounds containing alphabeta-unsaturation with respect to the functional group may be employed. Accordingly, compounds such as acrylonitrile, acrolein, crotonaldehyde, cinnamaldehyde, mesityl oxide, etc., are useful.

Ethers suitable as Lewis bases include the heterocyclic ethers, such as tetrahydrofuran, tetrahydropyran, dioxane, etc.

Exemplary of the hydrocarbyl esters of sulfur acids are the sulfoxidcs and sulfides, such as dimethyl sulfoxide and dimethyl sulfide. Heterocyclic sulfur compounds which may be used as Lewis bases include thiophene, thiozole, and 2-chlorothiophene.

Among the organic derivatives of Group VA elements which are useful are the trihydrocarbyl esters of Group VA element having an atomic weight of from about 30 to about 209. Thus, triethylphosphite, tri(2-ethylhexyl) phosphite, di(2-ethylhexyl) hydrogen phosphite, triphenylphosphite, di(p-tolyl) hydrogen phosphite, tri(p-tolyl) phosphite, triphenylphosphine, triethylarsine, triphenylarsine, triphenylstibine, triphenylantimonite, and triethylbismuthine may be employed as Lewis bases. Organic derivatives of nitrogen may also be successfully employed. Accordingly, amines such as trimethylamine, dioctylamine, tricyclohexylamine, triphenylamine, aniline, N-methylaniline, ethylene diamine and ethanolamine are useful. Likewise, heterocyclic nitrogen compounds including pyrrole, pyridene, pyrazole, 3-pyrroline, pyrrolidine, pyrimidine, purine, quinoline, isoquinoline and carbozole are operable. The organic derivatives of nitrogen which are especially preferred Lewis bases are the acylamido compounds, particularly those corresponding to the formula:

wherein R alone is selected from the group consisting of hydrogen, hydrocarbyl and substituted hydrocarbyl radicals, R alone is selected from the group consisting of R hydroxy, hydrocarboxy, nitroso, amino, carbonyl, and

radicals, R alone is selected from the group consisting N and each represent a heterocyclic radical having to 6 inclusive ring members. It will, of course, be understood that the broken lines in the above formula between R and R as well as between R and R indicate that such chemical bonds are optional. Suitable acylamido compounds include amides, such as acetamide, benzamide, succinamide, Nmethylacetamide, N,N-diethylacetamide, and N,Ndimethylformamide; imides, such as phthalimide, succinimide, N-nitrososuccinimide, N-phenylsuccinimide, N-phenylmaleirnide, N-mcthylsuccinimide, N-methylphthalimide, N-acetyltetrahydrophthalimide, li-benzoylsuccinimide, and N-benzoylphthalimide; ureas, such as urea, N,Ndiethylurea and N,N'-dimethylurea; carbarnates, such as ethylcarbamate and isopropylcarbamate; and lactams, such as caprolactam, pyrrolidone -butylrolactam), pipericlone (-valerolactam), N-nitr0so2-pyrrolidone, N- methyl-Z-pyrrolidone, N-vinyl-Z-pyrrolidone, N-acetyl-2- pyrrolidone, N-acetyl-ecaprolactam, N-benzoyl-e-caprolactam, N-benzoyl 5 vaierolactam, N-ethylcarbamyl-ecaprolactam, N propionyl-w-caprolactam, N-tolyl-w-decanolactam, S-methyhN-methyl-2-pyrrolidone, 4-methyl- N methyl-Z-pyrrolidone, 4ethyl-N-vinyl-Z-pyrrolidone, and N-methyl-2-piperidone.

In accordance with one preferred embodiment of the invention, a conjugated diolefin, particularly 1,3-butadiene, is employed as the Lewis base. Thus, the oligomerization reaction contemplated by the invention may be effected by admixing in a suitable inert solvent the nickel compound, reducing agent, carbon monoxide and an excess of butadiene or like conjugated diolefin with or without co-monomer, whereby an active butadiene complex of nickel (0) is formed which catalyzes the oligomerization of the remaining butadiene. Alternatively, the catalyst may be pre-formed and then contacted with butadiene monomer to effect the oligornerization reaction.

In accordance with another preferred embodiment of the invention, an organic derivative of nitrogen, particularly an aeylamido compound corresponding to the aforementioned formula, e.g. a lactam, is employed in conjunction with 1,3-butadiene as a Lewis base, whereby particularly useful catalyst compositions are prepared which reduce the formation of low molecular weight solid polymeric by-products of the oligomerization process.

In preparing the catalyst compositions, the reducing agent may be employed in an amount such that the molar ratio of reducing agent to nickel (positive valence) compound is from about 0.1:1 to about 50:1, although it is seldom necessary or desirable to operate outside of the preferred range of from about 0.25:1 toabout :1, and particularly from about 1:1 to about 12:1. The carbon monoxide may be suitably employed in a molar ratio to nickel of from about 0.3:1 to about 3.5 :1, preferably 0.5:1 to about 1.5:1. When butadiene or like conjugated diolefin is used as the Lewis base, as little as about 0.5 mole of butadiene per mole of nickel compound is suitable, preferably at least about 2 moles of butadiene per mole of nickel. There is, of course, no upper limit on the amount of butadiene which may be present during catalyst formation, since, as noted above, the catalyst may be prepared in the presence of an excess of butadiene, whereby the active butadiene complex of nickel (0) so formed catalyzes the remaining butadiene. When another Lewis base, such as an acylamido compound is used in lieu of or in conjunction with butadiene in preparing the catalyst composition, the molar ratio of the Lewis base to nickel may suitably range from about 0.511 to about 6:1, particularly from about 2.5 :1 to about 3.5: 1.

The oligomerization reaction of the invention is preferably carried out by contacting the conjugated diene with or without co-monomer in an inert organic solvent with the catalyst composition. The solvent used in preparing the catalyst and conducting the oligomerization reaction may be any inert organic solvent, such as benzene, toluene, petroleum naphtha, hexane, heptane, isooctane, eyclohexane, etc. The temperature at which the reaction is conducted may vary over a wide range, such as from about 0 C. to about 180 C., although the range of 20 C. to 150 C., particularly 30 C. to 100 C., is generally most preferred. In general, reactions conducted at temperatures below about 20 to 30 C. are quite slow, while operating temperatures above about 100-150 C. may result in diminished yields of the desired oligorner product. Furthermore, in co-oligomerization of butadiene with ethylene higher reaction temperatures tend to favor the formation of linear decatriene product. When it is desired to produce predominately l,5-cycl0decadiene, temperatures below C. are preferred. Optimum pressure is dependent on the particular monomer(s) oligomerized. Thus, in the oligomerization of 1,3-butadiene, the reaction pressure may range from about 10 to about 500 p.s.i.g., or higher. On the other hand, the co-oligomerization of butacliene and ethylene may be advantageously conducted using pressures up to about 3000 p.s.i.g., or higher. The concentration of catalyst in the reaction mixture may advantageously range from about 0.01 to about 10% by Weight of the monomer(s), although concentrations within in the range of 0.1% to about 2.0% are usually most preferred.

if desired, polymerization inhibitors may also be included in the reaction mixture, for instance in an amount of from about 0.001% to about 4.0% based on the weight of the monomer feed. Suitable polymerization inhibitors are well-known to the art and include phenol, catechol, p-tert-butyl catechol, resorcinol and hydroquinone.

Following completion of the reaction, conventional techniques may be employed to deactivate the catalyst composition and recover the desired oligomer products. One suitable catalyst deactivation procedure involves contacting the reaction mixture with aqueous methanol.

In producing co-oligomers of butadiene and ethylene or butadiene and styrene, for instance 1,5-cyclodecadiene or 1-phenyl-3,7-cyclodecadiene, butadiene and the comonomer may be employed in molar ratios of about 1:1 to about 3:1 as the feed. However, butadiene: co-monomer mole ratios of from about 0.05 to about 20:1 may also be used. It should be noted, however, that lower butadiene: co-monomer molar ratios within the specified ranges tend to favor the formation of linear oligomer.

The invention Will now be further described in reference to the following specific examples, which are presented solely for the purpose of illustration and are not to be interpreted as limiting the scope of the invention.

Examples 12 In each of Examples 1-2, a clean dry 300 ml. stainless steel autoclave equipped with a magnetic stirrer was flushed with argon, evacuated and then charged with 25 ml. of benzene, 3.9 rnillimoles of nickel. acetylacetonate, 19.5 millimoles of triethylaluminum and grams of butadiene. In Example 2, which represents the run in accordance with the present invention, carbon monoxide (3.9 millimoles) was also added to the autoclave prior to reducing the valence of nickel :by the addition of triethylal-uminum. Following charging of the reactants, the contents of the autoclave were stirred and the temperature was raised to 80 C. The reaction in each case was carried out to a butadiene conversion of about 85-90%. Yield of 1,5,9-cyclodcdecatriene was high in both cases. However, in the run employing carbon monoxide in accordance with the invention (Example 2), the desired butadiene conversion was obtained at a reaction time of 25 minutes, while a reaction time of minutes was re- Examples 3-4 The procedures of Examples 1 and 2 were substantially repeated except that 11.7 millimoles of N-methyl-2-pyrrolidone were charged to the autoclave in each case as a co-Lewis base with 1,3-butadiene. A bntadiene conver sion of 85-90% was achieved at about 180 minutes when CO was not added during catalyst preparation (Example 3), and at about 30 minutes when CO was employed during catalyst preparation (Example 4). The employment of N-methylpyrrol-idone as a Lewis base in conjunction with butacliene substantially decreased formation of undesirable low molecular weight solid polymer.

Examples 5-6 Examples 5-6 illustrate the preparation of 1,5-cyclodecadiene from a monomer mixture of 1,3-butadiene and ethylene.

In Example 5, a 500 ml. autoclave was charged with 11.2 grams of a 9.0% solution of nickel acetylncetonate in benzene, 75 ml. of benzene, 6.5 ml. of a 20% solution of tr-iethylaluminum in benzene, 10 grams of butadiene Besides increasing reaction rate, it will also be noted from a comparison of the data set forth in Tables 1 and 2 that significantly higher 1,5-cyclodecadiene selectivity was obtained by carrying out the butadiene-ethylene cooligomerization reaction in accordance with the present invention (i.e., Example 6).

Examples 7-9 The following co-oligomerization reactions of butadiene and ethylene were carried out in accordance with Examples 7-9, which demonstrate the necessity of a Lewis base, e.g. butadiene, during catalyst preparation. In Ex ample 7, triethylaluminum, nickel acetylacetonate and carbon monoxide were mixed together in a mole ratio of 2.5: 1 :1 prior to charging the autoclave with the monomers. In Example 8, triethylaluminum, nickel acetylacetonate and carbon monoxide were mixed together in the same mole ratio in the presence of ethylene only, while in Example 9, the catalyst components were mixed together in the presence of both butadiene and ethylene. The reaction conditions and results were as set forth in Table 3, below. In Table 3, 1,5-cyolodecadiene is abbreviated as C D 1,4,9-decatriene is abbreviated as nC T; 1,5,9-cyclododecatriene is abbreviated as CDT.

TABLE 3 Cat. Butadiene: Butadiene Ethylene Product Selectivity Example Reaction Temp. Cone. Ethylene Conversion Conversion Time (hrs) 0.) (percent Mole Ratio (percent wt.) (percent wt.) C10D5 nCmT CDT Others Non wt volatile 6 6O 1. 75:1 No Conversion 6 60 0 5 1. 75:1 Low Conversion Qualitative VPC shows CmD 6 6O 0 5 1.75:1 90 6 68.3 4. 1 15.4 9.5 2.3

and 60 grams of ethylene. The reaction temperature was Example raised to about 50 C. and the contents of the autoclave were stirred. While maintaining temperature of 50 C., 180 grams of butadiene were pumped into the autoclave by means of a Lapp pump at a rate such that the reaction pressure was maintained at 80-100 p.s.i.g. Approximately hours were required for butadiene addition.

The recovered reaction mixture was analyzed by gas chromotography to give the following selectivities:

Non-volatiles 10.1

In accordance with Example 6, 0.11 gram of carbon monoxide were also charged to the autoclave prior to adding the bulk of the butadiene. With the autoclave contents at 50 C., 180 grams of butadiene were introduced at a rate such that the reaction pressure was maintained between about 80 to 100 p.s.i.g. Only 2 /2 hours were required to add the requisite amount of butadiene compared to about 20 hours in Example 5, which indicates that the presence of carbon monoxide during catalyst formation enhances the reaction rate of the subsequent oligomerization reaction. Gas chromotography indicated the following product selectivities:

TABLE 2 Wt. percent sults:

TABLE 4 Wt., percent 1,5-cyclodecadiene 72.4 1,4,9-decatriene 3.8 1,5,9-cyclod0decatriene 12.5 Others 7.3 Non-volatiles 4.0

Examples 11-13 Examples 11-13 further illustrate the advantageous use of N-methyl-Z-pyrrolidone in conjunction with butadiene as a Lewis base in butadiene-ethylene co-oligornerization.

Triethylaluminum, carbon monoxide, N-methylpyrrolidone, nickel naphthenate, butadiene and ethylene were mixed together in a benzene solvent in the mole ratios cyciooctadiene and vinykyclchexene 4 Q noted in Table 5, below, and the co-oligomerization of 1 4 gdecamene 3 0 butadiene and ethylene was conducted with the following pywclodecadienc 775 results. In the table, N1 represents nickel contained 1n 1,5,9-cyclododecatriene 14.4 ickel naphthenate, N-MP represents N-methyl-pyr- Non-volatiles 1.1 rolidone and TEA represents tn'ethylaluminum.

TABLE 5 Mole Ratios Catalyst Temp. Time Conv., Selectivities Example Cone. 0.) (his) Percent TEA:NMP:CO:Ni Butadienezethylene tpcreentwt.) COD CmT OmD CDT Non Vol.

4mm 1 so 4 on 3.1 5.2 10.2 12.0 1:2:lz1 1 so 4 as 5.3 2.4 71..) .7 no man: 1. so 1 at 4.0 1.0 7m 15.5 2.0

9 It will be noted from the above data set forth in Table that as the concentration of N-methylpyrrolidone increased, selectivity of 1,5-cyclodecadiene increased and formation of undesirable low molecular weight solid polymer (non volatiles) significantly decreased.

Examples 14-18 TABLE 7 Butadiene conversion (percent) 81 Selectivities (wt., percent):

1,5-cyclooctadiene 10.8 1,5-cyclodecadiene 9.0 1,4,9-decatriene 25.0 1,5,9-cyclododecatriene 41.0 Non-volatiles 14.2

Examples -22 These examples illustrate the use of various acylamido compounds other than N-methyl-Z-pyrrolidone in conjunction with butadiene in preparing active nickel (0) catalysts complexes used in the practice of the present invention. In each case, triethylaluminum, the acylamido compound, carbon monoxide and nickel acetylacetonate were admixed in a molar ratio of 4-:2.5:1:ll in the presence of butadiene and ethylene in a molar ratio of 1.75:1 in benzene solvent. Catalyst concentration was 1.0% W. The

TABLE 6 Selectivity Example Reducing agent Conv.,

percent COD C D CDT Nonvolatile 14 Phenyhnagnesium bromide .14. 5 55. 5 18. 4 5.3 15.. Butyllithi 25 38.5 44.5 10.8 6.1 10.. 10 Qualitative VPC shows IDDE 17... 85 5.2 5.0 71. 5 14. 2 2.0 18 Dibutylaluminum hyd 91 6.8 73.0 13.0 2 1 It will be noted that While aluminum compounds are the preferred reducing agents, other reducing agents may also be used with some advantage.

operating temperature was about C., and the reaction time was about 4 hours in each case. The results were as follows:

TABLE 8 Butadiene Selectivities Example Acylamido Comp. Conv. (wt.

percent) COD C 'l 01 13 CDT Non- Vol.

N, N-dimcthyl formamide. 83 3. 4 6.4 72. 6 11.1 5.9 Queeinamide 71 4. 5 8.1 66. 6 10.0 10. I N-methyl wpiperidone 77 3. 6 10.1 68.5 10. 9 7.1

Example 19 As previously noted, when it is desired to produce prcdominantly cyclodecadiene product of the oligomerization of butadiene and ethylene relatively low reaction temperatures, e.g. below about 80 C. are preferred. Conversely, increased yields of 1,4,9-decatriene may be obtained by carrying out the reaction at higher temperatures, as is illustrated by the present example.

Examples 23-26 These examples illustrate the use of various Lewis bases other than acylarnido compounds in conjunction with butadiene in preparing the active nickel (0) catalysts complexes used in the practice of the invention. In each case, triethylaluminum, co-Lewis base, carbon monoxide and nickel acetylacetonate were admixed in a molar ratio of 4:3:1:1 in the presence of butadiene and ethylene in a molar ratio of 1.75:1 in benzene solvent. Catalyst concentration was 1.0% w. The operating temperature was about 50 C. and the reaction time was about 4 hours in each case. The results were as follows:

TABLE 9 Butadiene Selectivities Example (Do-Lewis Base Conversion (wt. percent) GOD Cwl GmD5 CDT Non- Volatile 81 3. 5 10. 1 07. 6 10.8 8. 1 59 2. 9 9. 9 68. 5 5.2 13. 5 3. 7 8.1 02.1 7. 6 18. 4 26 Triphenyl-phosphine 54 8.6 7.2 61.3 12.1 10.8

Triethylaluminum, N-methylpyrrolidone, carbon monoxide and nickel acetylacetonate were admixed in a mole ratio of 4:3:l:1 in the presence of butadiene and ethylene in a mole ratio of about 2:1 in benzene solvent. The co-oligornerization reaction was carried out at a temperature of 100 C. for two (2) hours with the following results:

Examples 27-32 T hese examples illustrate the effect of varying butadiene:ethylene mole ratios on product selectivity.

Butadiene and ethylene were co-oligomerized in benzene solvent at about 50 C. over a period of four (4) hours in the presence of a catalyst prepared in situ by admixing triethylaluminum, carbon monoxide, N-methyl- 1 1 pyrrolidone and nickel acetylacetonate in a molar ratio of 4: 1 :2.5 1. The various butadienezethylene mole ratios and oligomer selectivities were as follows:

understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended to TABLE Conv. Sclectivities Example Mole Ratio Butudiene butadieue ethylene (porogit C OD C mT C10D CDT Non-Vol.

Example 33 A catalyst composition was prepared by mixing in ben- Examples 34-40 These examples illustrate the co-oligomerization of butadiene and styrene to form phenyl-substituted linear and cyclic oligomers. The reactions were carried out in a cover all such changes and modifications in the appended claims:

Therefore, we claim:

I. An oligomeiization process which comprises contacting under substantially anhydrous conditions a monomeric feed comprising the aliphatic conjugated diolefin,

20 butadiene, with a catalyst composition produced by admixing under substantially anhydrous conditions a nickel compound selected from the group consisting of nickel (11) and nickel (III) compounds; a reducing agent capable of reducing the valence of nickel to below 2, carbon monoxide and a molecular organic Lewis base.

2. Process as in claim 1 wherein said reducing agent is selected from the group consisting of hydrogen, the hydrazines, metals of Groups I-A, IIA, rIIB, IIIA and IV-A and hydride and organometallic compounds of said metals stirred, 300 I111. autoclave according to the conditions set and of boron.

forth in Table 11.

TABLE 11 Example 3. Process as in claim 2 wherein said reducing agent Autoclave Charge:

Benzene solvent (ml.) 35 35 35 35 35 Nickel aeetylacetonate 3. 9 3. 9 8. 9

(mmoles).

Nickel naphthenate (mmoles) 3. 9 3. 9

Nickel chloride (mmoles) N, N-dimethyl l'ormamide 11. 7

(Inmoles).

N-methyl-Z-pyrrolidone (mmoles).

Carbon monoxide (mmoles) Triethylaluminum (mmoles) Diethylethoxyaluminum (mmoles). Butadienc (moles). 1 1 1 l Styrene (m0les). 0 5 O 5 0.6 0 5 0 6 Oligomerization Con Reaction time (hrs) 1 1 2 2 1 Reaction Temp. C C. Total Reaction Pressur p.s.i.g.) Butadiene Conversion percent).

Product Selectivity (wt. percent):

Vinylcyclohexene l,5-cyclooctadiene 1,5,9-cyclododecatrien 1-phenyl-3,7-cyclodecadie l-phenyl-l,4,9-decatriene 4 Non-volatile It will be noted from the data of Table 11 that butadiene and styrene may be rapidly co-oligomerized by the present invention to high yields of 1-phenyl-3,7-cyclodecadiene and l-phenyl-l,4,9-decatriene. The selectivity of the phenyl-substituted cyclodecadiene may be increased by operating at lower reaction temperatures, cg. below about 80 C.

As is known in the art, the linear triene oligomers produced in accordance with this invention, such as 1,4,9- decatriene and l-phenyl. 1,5,9-decatriene, are useful as third monomers in the manufacture of ethylene-propylene terpolymers. The unsaturated cyclic oligomer products,

such as 1,5,9-cyclododecatriene, 1,5-cyclodecadiene and 1-phenyl-3,7-cycloclecadiene may be converted by known procedures to useful dibasic acids or like useful compounds.

While the invention hus been described above with respect to certain preferred embodiments thereof, it will be is represented by the formula R A X wherein R is a radical selected from the group consisting of hydride and hydrocarbyl radicals, X is a radical selected from the group consisting of halide and hydrocarboxy radicals, a is from 1 to 3, b is from 0 to 2 and the sum of a plus bis 3.

4. Process as in claim 3 wherein said reducing agent is a trialkylaluminum compound.

5. Process as in claim 1 wherein the valence of nickel is reduced to 0 upon mixing with said reducing agent.

6. Process as in claim 1 wherein said Lewis base is the aliphatic conjugated diolefin butadiene.

7. Process as in claim ll wherein said Lewis base is an organic derivative of a Group V-A element.

8. Process as in claim 7 wherein said Group VA element is nitrogen.

9. Process as in claim 8 wherein said Lewis base is an acylamido compound.

10. Process as in claim 9 wherein said acylamido compound is represented by the formula:

wherein R alone is selected from the group consisting of hydrogen, hydrocarbyl and substituted hydrocarbyl radicals, R alone is selected from the group consisting of R hydroxy, hydrocarboxy, nitroso, amino, carbonyl and O in,

radicals, R alone is selected :from the group consisting of hyd'rocarbyl, substituted hydrocarbyl, hydrocarboxy and amino radicals, and

N- and each represent a heterocyclic radical having 5-6 inclusive carbon atoms.

11. Process as in claim 1 wherein said monomeric feed comprises a mixture of said conjugated diolefin and a comonomer selected from the group consisting of hydrocarbons having the formula:

A CH2:

H wherein A is selected from the group consisting of hydrogen and phenyl.

12. Process as in claim 11 wherein said monomeric feed is an admixture of 1,3-butadiene and said hydrocarbon having the formula:

the mole ratio said 1,3-butadiene to said hydrocarbon co monomer being from about 0.5 :1 to about 20:1.

13. Process as in claim 1 wherein the mole ratio of said reducing agent to said nickel compound is =frorn about 0.1:1 to about 50:1, the mole ratio of carbon monoxide to said nickel compound is from about 0.3:1 to about 3.5: 1, and the mole ratio of said molecular organic Lewis base to said nickel compound is at least 0.5: 1.

14. Process as in claim 13 wherein the mole ratio of said reducing agent to said nickel compound is from about 1:1 to about 12:1, the mole ratio of said carbon monoxide to said nickel compound is from about 0.5:1 to about 15:1 and the mole ratio of said Lewis base to said nickel compound is at least 2:1.

15. An oligomerization process which comprises contacting under substantially anhydrous conditions a monomeric feed comprising the aliphatic conjugated diolefin, butadiene, with a catalyst com-position produced by admixing under substantially anhydrous conditions, a nickel compound selected from the group consisting of nickel (II) and nickel (III) compounds, at reducing agent capable of reducing the valence of nickel to below 2, carbon monoxide, a first molecular organic Lewis base consisting of the conjugated aliphatic diolefin butadiene and a second molecular organic Lewis base consisting of an organic derivative of a Group VA element.

16. Process as in claim 15 wherein said Group V-A element is nitrogen.

17. Process as in claim 16 wherein said organic derivative of nitrogen is an acylamido compound represented by the formula:

14 wherein R alone is selected from the group consisting of hydrogen, hydrocarbyl and substituted hydrocarbyl radicals, R alone is selected from the group consisting of R hydroxy, hydrocarboxy, nitroso, amino, carbonyl and radicals, R alone is selected from the group consisting of hydrocarbyl, substituted hydrocarb-yl, hydrocarboxy and amino radicals, and

each represent a heterocyclic radical having 5-6 inclusive carbon atoms.

18. Process as in claim 15 wherein the valence of nickel is reduced to 0 upon mixing with said reducing agent.

19. Process as in claim 15 wherein the molar ratio of said reducing agent to said nickel compound is from about 0.121 to about 50:1, the molar ratio of said first Lewis base to said nickel compound is at least 0.521, the molar ratio of said second Lewis base to said nickel compound is from about 0.5:1 to about 6:1 and the molar ratio of carbon monoxide to said nickel compound is from about 0.3:1 to about 3.5:1.

20. Process as in claim 19 wherein the molar ratio of said reducing agent to said nickel compound is from about 1:1 to about 12:1, the molar ratio of said first Lewis base to said nickel compound is at least about 2:1, the molar ratio of said second Lewis base to said nickel compound is from about 2.5:1 to about 35:1 and the molar ratio of carbon monoxide to said nickel compound is from about 0.511 to about 1.5:1.

21. Process for oligomerizing a monomeric feed comprising L3-butadiene which comprises contacting said monomeric feed under substantially anhydrous conditions at a temperature of from about 0 C. to about C. with a nickel (0) catalyst composition prepared by admixing under substantially anhydrous conditions an organic nickel (II) compound, triethylalurninum, carbon monoxide, and a first molecular organic Lewis base consisting of 1,3-butadiene, the molar ratio of triethylaluminurn to said organic nickel compound being from about 1:1 to about 12: 1, the molar ratio of carbon monoxide to said organic nickel compound being from about 0.5:1 to about 1.5:1 and the molar ratio of said first Lewis base to said organic nickel compound being at 'least 2: 1.

22. Process as in claim 22 wherein a second molecular organic Lewis base consisting of N-methyl-Z-pyrrolidone is also admixed with said organic nickel (2) compound, triethylaluminum, carbon monoxide and said first organic molecular Lewis base, the molar ratio of N-methyl-2- pyrro'lidone to organic nickel compound being from about 2.521 to about 35:1.

23. Process as in claim 22 wherein said monomeric feed is an admixture of 1,3-butadiene and a hydrocarbon co-monomer having the formula:

wherein A is selected from the group consisting of hydrogen and phenyl radicals, the mole ratio of 1,3-butadiene to said hydrocarbon co monomer being from about 0.5:1 to about 20:1.

'24. Process for producing predominantly 1,5-cyclodecadiene which comprises contacting under substantially anhydrous conditions at a temperature of from about 20 C. to about 80 C. and admixture of 1,3-butadiene and ethylene in a mole ratio of from about 1:1 to about 3:1 with a nickel (0) catalyst composition prepared by admixing under substantially anhydrous conditions an organic nickel (II) compound, triethylaluminum, carbon monoxide, and a first molecular organic Lewis base consisting of 1,3-butadiene, the molar ratio of triethylaluminum to said organic nickel compound being from about 1:1 to about 12: 1, the molar ratio of carbon monoxide to said organic nickel compound being from about 0.5:1 to about 1.5 :1 and the molar ratio of said first Lewis base to said organic nickel compound being at least 2:1.

25. Process as in claim 24 wherein a second molecular organic Lewis base consisting of N-methyl-2pyrrolidone is also admixed with said organic nickel (II) compound, triethylaluminum, carbon monoxide and said first organic molecular Lewis base, the molar ratio of N-methyl-Z-pyrrolidone to organic nickel compound being from about 2.5:1 to about 35:1.

References Cited UNITED STATES PATENTS Reppe et al. 260-439 Reppe et a1. 260-439 Lautenschlager et al. 260-439 Nowlin et a1. 260-683.15

Mueller 260-666 Kirk 260-666 Wilke et al. 260-666 Seibt et a1 260-666 Knoth 260-439 Roest et al. 2613-6832 Clark 260666 Zuech 260-666 Great Britain.

0 DELBERT E. GANTZ, Primary Examiner.

V. OKEEFE, Assistant Examiner. 

1. AN OLIGOMERIZATION PROCESS WHICH COMPRISES CONTACTING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS A MONOMERIC FEED COMPRISING THE ALIPHATIC CONJUGATED DIOLEFIN, BUTADIENE, WITH A CATALYST COMPOSITION PRODUCED BY ADMIXING UNDER SUBSTANTIALLY ANHYDROUS CONDITIONS A NICEL COMPOUND SELECTED FROM THE GROUP CONSISTING OF NICKEL (II) AND NICKEL (III) COMPOUNDS; A REDUCING AGENT CAPABLE OF REDUCING THE VALENCE OF NICKEL TO BELOW 2, CAROBN MONOXIDE AND A MOLECULAR ORGANIC LEWIS BASE. 